The invention provides a system and method for inspecting a belt defect through employing a laser vibration meter. A test signal of the laser vibration meter serves as a detection signal, and vibration pulses generated when the belt fault extrudes a belt wheel are used for precisely locking the position of the defect, thereby solving problems that a moving belt with big deformation is difficult to inspect through a vibration sensor and the position of the defect is more difficulty to determine accurately. The method is suitable for the vibration testing of lighter parts with big deformation and smaller surfaces, and there is no contact between testing equipment and a tested part. The testing method is simple, is low in cost, and is accurate in defect inspection.